Background immunity is well established in the medical literature. And the role of T-cell immunity against covid has been widely recognised for more than a year. This is why most people get little or no symptoms from SARS-CoV-2 and children are virtually unaffected.
A "SIGNIFICANT number" of Brits are naturally immune to coronavirus - without EVER being infected, a top scientist has said.
Sir John Bell, regius professor of medicine at Oxford University, said it's likely a large amount of the population already have a "background level" of protection against Covid-19.
Research has shown that being infected with other coronaviruses, such as the common cold, could offersome protection against the new bug.
Recent studies have found that a separate part of the immune system, known as T-cells, were already had in the blood of some patients who had recovered from Covid.
Similarly to antibodies, they are made in response to an infection - and remain afterwards - suggesting that previous exposure to other coronaviruses had somehowprimed their T-cells to recognise and attack Covid-19.
It's thought they could be responsible for stopping the virus in people who never show symptoms.
But more importantly, those T-cells die off in older people, which could explain why the elderly are at higher risk of severe illness..
